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      <title>介绍下XSS跨站脚本注入 - 交互式测验</title>
      <style>
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            max-width: 900px; /* Wider to accommodate buttons */
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        .quiz-body {
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        .progress-bar {
            display: none; /* 隐藏进度条 */
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        #question-text {
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          font-weight: 500;
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          margin-bottom: 25px;
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        .options-list {
          list-style: none;
          padding: 0;
          margin: 0;
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        .option-item {
          background-color: #f8f9fa;
          border: 1px solid #dee2e6;
          border-radius: 8px;
          padding: 15px;
          margin-bottom: 12px;
          cursor: pointer;
          transition: background-color 0.2s ease, border-color 0.2s ease;
        }

        .option-item:hover {
          background-color: #e9ecef;
        }
        
        .option-item.selected {
            background-color: #d1e7fd;
            border-color: #4a90e2;
        }

        .quiz-footer {
          padding: 20px 30px;
          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
          border: none;
          border-radius: 8px;
          padding: 10px 20px;
          font-size: 16px;
          font-weight: 500;
          cursor: pointer;
          transition: background-color 0.2s ease, transform 0.2s ease;
          box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        
        #next-btn {
            background-color: #28a745;
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        .nav-btn:hover {
          background-color: #357abd;
          transform: scale(1.05);
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        .nav-btn:disabled {
            background-color: #a0c3e8;
            cursor: not-allowed;
            opacity: 0.7;
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        #result-container {
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        .result-box {
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
        }
        
        .result-box.correct {
            background-color: #d4edda;
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            color: #155724;
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        .result-box h3 {
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        .source-text {
            font-style: italic;
            font-size: 14px;
            margin-top: 15px;
            color: #555;
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            padding: 40px;
            text-align: center;
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        .final-score-container h2 {
            margin-top: 0;
            margin-bottom: 30px;
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            display: flex;
            justify-content: center;
            gap: 20px;
            margin-bottom: 40px;
            flex-wrap: wrap;
        }
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            background-color: #f8f9fa;
            border-radius: 12px;
            padding: 20px;
            width: 180px;
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            font-size: 16px;
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        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>介绍下XSS跨站脚本注入 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "一位用户在某网站的评论区发布了一条包含恶意JavaScript代码的评论，该评论被保存到服务器数据库中。当其他用户浏览该评论时，恶意代码在他们的浏览器中执行。这属于哪种类型的XSS攻击？",
    "options": [
      "反射型XSS (Reflected XSS)",
      "基于DOM的XSS (DOM-Based XSS)",
      "存储型XSS (Stored XSS)",
      "服务器端请求伪造 (SSRF)"
    ],
    "correctAnswerIndex": 2,
    "explanation": "这种攻击的特点是恶意脚本被永久或半永久地存储在目标服务器上（例如数据库、消息论坛、评论字段等）。当其他用户请求包含该恶意脚本的内容时，服务器会将其作为正常内容发送给用户的浏览器执行，因此被称为存储型XSS。",
    "source": "文档中「1.2 分类」部分的「存储型XSS（Stored XSS）」",
    "hint": "思考一下恶意代码的“生命周期”：它是在哪里被“存放”起来，等待其他用户访问的？"
  },
  {
    "question": "在防御XSS攻击时，将用户输入的特殊字符如 `<` 转换为 `&lt;` 的主要目的是什么？",
    "options": [
      "防止浏览器将用户输入的内容解析为可执行的HTML标签或脚本",
      "验证用户输入的格式是否符合规定",
      "减少数据库的存储空间",
      "提高页面的加载速度"
    ],
    "correctAnswerIndex": 0,
    "explanation": "这种技术被称为“HTML编码”或“HTML实体编码”。其核心目的是将具有特殊含义的字符（如 `<`, `>`）转换为它们的HTML实体表示。这样浏览器在渲染页面时，会将它们当作纯文本来显示，而不是作为HTML标签来解析执行，从而从根本上阻止了XSS攻击的发生。",
    "source": "文档中「4.2 输出编码」部分的「HTML编码」",
    "hint": "这个操作的目的是改变浏览器对特定字符的“看法”，让它认为这只是普通文本。"
  },
  {
    "question": "哪种XSS攻击类型的主要特点是，攻击者将恶意代码嵌入URL中，诱导用户点击，恶意脚本被服务器“反射”回用户的浏览器并立即执行？",
    "options": [
      "存储型XSS (Stored XSS)",
      "反射型XSS (Reflected XSS)",
      "基于DOM的XSS (DOM-Based XSS)",
      "SQL注入 (SQL Injection)"
    ],
    "correctAnswerIndex": 1,
    "explanation": "反射型XSS是一种非持久性的攻击。攻击载荷通常存在于URL的参数中。当用户点击这个恶意链接时，Web应用程序会读取URL中的参数，未经充分处理就直接在响应页面中输出，导致恶意脚本在用户的浏览器上执行，这个过程就像是从服务器“反射”回来一样。",
    "source": "文档中「1.2 分类」部分的「反射型XSS（Reflected XSS）」",
    "hint": "这种攻击的名称本身就形象地描述了它的工作方式，恶意代码像是被服务器“弹回”给了浏览器。"
  },
  {
    "question": "XSS攻击可能导致多种严重后果。以下哪项是攻击者利用XSS窃取用户身份凭证，进而冒充用户进行操作的常用手段？",
    "options": [
      "直接获取服务器的root权限",
      "加密服务器硬盘进行勒索",
      "窃取用户的Cookie信息，从而劫持会话",
      "导致服务器物理损坏"
    ],
    "correctAnswerIndex": 2,
    "explanation": "由于恶意脚本在用户的浏览器环境中执行，因此它可以访问该网站域下的Cookie。攻击者常常通过XSS窃取包含会话标识符（Session ID）的Cookie，然后利用这个Cookie来伪装成受害者与服务器进行交互，这种行为被称为“会话劫持”。",
    "source": "文档中「3. XSS攻击的影响」部分的「窃取敏感信息」和「劫持会话」",
    "hint": "攻击者如何在不知道你的密码的情况下，让服务器相信他就是你？他们需要窃取一个关键的“临时通行证”。"
  },
  {
    "question": "内容安全策略（Content Security Policy, CSP）是如何作为一道重要防线来抵御XSS攻击的？",
    "options": [
      "自动扫描并删除服务器数据库中的恶意代码",
      "通过定义一个可信的资源来源白名单，限制浏览器加载和执行未授权的脚本",
      "对所有用户输入进行加密处理，使其无法被执行",
      "强制所有用户必须进行双因素认证"
    ],
    "correctAnswerIndex": 1,
    "explanation": "CSP通过一个HTTP响应头来工作，它允许网站管理员告诉浏览器哪些来源（域名）是可信的。即使攻击者成功地在页面中注入了恶意脚本，如果该脚本的来源（或其本身是内联脚本而被策略禁止）不在CSP设定的白名单中，浏览器也会拒绝执行它，从而有效地遏制了XSS攻击的影响。",
    "source": "文档中「4.3 内容安全策略（CSP）」部分",
    "hint": "CSP就像一个“安保策略”，它规定了只有来自“受信任列表”上的脚本才能被浏览器执行。"
  },
  {
    "question": "有一种XSS攻击，其攻击载荷的注入和执行完全发生在客户端，通过JavaScript直接修改页面的DOM（文档对象模型）结构来触发，服务器可能对此毫不知情。这种攻击类型是？",
    "options": [
      "基于DOM的XSS (DOM-Based XSS)",
      "存储型XSS (Stored XSS)",
      "反射型XSS (Reflected XSS)",
      "跨站请求伪造 (CSRF)"
    ],
    "correctAnswerIndex": 0,
    "explanation": "基于DOM的XSS的独特之处在于，恶意负载由客户端的脚本进行处理和执行，而不是服务器。攻击者利用不安全的客户端JavaScript代码（例如，代码从URL片段`#`中获取内容并直接用`innerHTML`写入页面）来操纵DOM，从而执行恶意脚本。",
    "source": "文档中「1.2 分类」部分的「基于DOM的XSS（DOM-Based XSS）」",
    "hint": "这种攻击的“舞台”是浏览器中的文档对象模型（DOM），而不是服务器的响应内容。"
  },
  {
    "question": "根据文档，为了建立一个纵深防御体系来全面地防范XSS攻击，以下哪项策略组合是最佳实践？",
    "options": [
      "仅在服务器端安装Web应用防火墙（WAF）",
      "只依赖现代前端框架（如React, Vue）的自动编码功能",
      "结合使用严格的输入验证、关键位置的输出编码以及内容安全策略（CSP）",
      "只对用户输入进行过滤，但不在输出时进行编码"
    ],
    "correctAnswerIndex": 2,
    "explanation": "单一的防御措施很难完全杜绝XSS。最佳实践是采用纵深防御策略：首先通过输入验证过滤掉明显的恶意数据；然后在将数据展示给用户时进行严格的输出编码，这是最核心的防御手段；最后通过部署CSP作为最后一道防线，即使前两层被绕过，也能在很大程度上阻止恶意脚本的执行。",
    "source": "文档中「4. 防御XSS攻击的策略」的整体内容，特别是对「4.1 输入验证和清理」、「4.2 输出编码」和「4.3 内容安全策略（CSP）」的综合理解",
    "hint": "安全防御讲究“层层设防”，单一的措施往往不够可靠。思考一下如何从输入到输出再到浏览器执行，都设置关卡。"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
          }

          updateProgress();

          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
            const li = document.createElement('li');
            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  